The invention relates generally to compositions useful in altering the migration and/or proliferative activity of smooth muscle cells, and to methods of using them, for example, to inhibit vascular stenosis including restenosis following surgical removal of atherosclerotic plaques.
Vascular smooth muscle cells (VSMC) of the aorta are situated in an interstitial extracellular matrix which contains glycoproteins, collagens, proteoglycans, and growth factors. VSMC in the normal vessel are in a growth arrested state under the control of homeostatic mechanisms that must be altered to permit cell migration and proliferation, two activities that are the hallmarks of many common diseases such as restenosis following endothelial injury and atherosclerosis. Recent studies have shown that migration of arterial VSMC from the media of the vessel into the intima is an important step in the development of arterial lesions. Clearly, reagents that can regulate VSMC migration and reorganization will be useful in managing the restenosis that can result from endothelial injury, for example, as the result of procedures such as angioplasty and endarterectomy.
Percutaneous transluminal coronary angioplasty (PCTA) is widely used as the primary treatment modality in many patients with coronary artery disease. Two problems associated with the procedure are restenosis after angioplasty or where the patient is not a candidate for angioplasty. Administration of compositions which can alter cell migration and reorganization in conjunction with angioplasty can reduce the possibility of restenosis. When reducing lumen obstruction by angioplasty is not an option, altering cell behavior, specifically the processes related to angiogenesis, may provide an alternative treatment for overcoming myocardial ischemia in patients with coronary artery disease.
The present invention relates to compositions for altering the migration and proliferative activity of smooth muscle cells. Migration-altering compositions include the proteins clusterin and gp38k, fragments thereof which retain the migration-altering activity, peptides derived from the proteins which possess the migration-altering activity, and polyclonal, monoclonal and recombinant humanized antibodies directed against the proteins and peptides and fragments thereof.
In one aspect, the invention relates to peptides and analogs thereof containing functionally equivalent amino acids that are derived from proteins intimately involved in vascular smooth muscle cell migration and reorganization. These peptides may be chemically synthesized, obtained by limited proteolytic digestion of the proteins or produced by recombinant technology.
In yet another aspect, the invention relates to polyclonal, monoclonal, and recombinant humanized antibodies, and fragments thereof, directed against proteins essential for migration, proliferation and tube formation of vascular endothelial cells.
In still another aspect, the invention relates to a DNA sequence which codes for an RNA that is complementary to and capable of binding to a transcribed sequence of clusterin.
In yet another aspect, the invention relates to a DNA sequence which codes for an RNA that is complementary to and capable of binding to a transcribed sequence of gp38k.
In a related aspect, the invention relates to a method of altering cell migration by contacting said cells with a migration-altering protein, polypeptide or polynucleotide composition derived from clusterin or gp38k.
In another related aspect, the invention relates to therapeutic methods involving surgical or intravenous introduction of such compositions directed to certain target cell populations, such as smooth muscle cells or cancer cells, requiring modulation to ameliorate a disease state, particularly for treating conditions such as stenosis following vascular trauma or disease, atheroclerosis, or cancer.
In another aspect, the invention relates to a method for inhibiting restenosis by preventing translation of the specific nucleic acid sequences which encode clusterin and gp38k. A nucleotide sequence which is complementary to and capable of binding to an mRNA which codes for these proteins can be used to reduce the amount of clusterin and gp38k constitutively produced in response to injury. Application of an antisense molecule of the type described may be administered prior to or contemporaneously with PCTA at the site where atherosclerotic plaques are to be removed.
In a closely related aspect, the invention relates to a method of reducing restenosis in a patient following angioplasty or endarterectomy comprising administering to a patient a therapeutically effective amount of an antibody directed against a migration-altering composition. The antibody is an anti-clusterin antibody or an anti-gp38k antibody, and it inhibits the chemotactic or mitotic activity of the migration-altering composition.
In yet another aspect, the invention relates to the use of migration-altering compositions as anti-tumor agents. Inhibition of angiogenesis deprives tumor cells of needed blood supply and leads to tumor cell death and diminution of the tumor.
In another aspect, when it is desirable to increase the vasculature, thereby providing a blood supply, local application of a migration altering composition can initiate the smooth muscle cell processes involved in angiogenesis and vasculogenesis.